Limits of self-assembly for nanotechnology

Robert F. Service writes an accessible summary in Science on How Far Can We Push Self-Assembly? On the current achievements of chemists using covalent bonding: “Using that trick, they have learned to combine as many as 1000 atoms into essentially any molecular configuration they please.” On the status of work using noncovalent bonding: “Chemists have learned to take advantage of these and other rules to design self-assembling systems with a modest degree of complexity.” On the need for these new techniques for making chips, etc.: “At some point, however, it will become cheaper to design and build them chemically from the bottom up…Self-assembly is also the only practical approach for building a wide variety of nanostructures.” Not covered in this brief essay is the next step: combining covalent, non-covalent, and 3D positioning techniques to build yet more complex systems.